Which of the following methods is permissible for obtaining disclosure?

Obtaining disclosure in a civil practice context is crucial for allowing parties to gather necessary information and evidence to support their claims or defenses. Depositions upon oral questions and interrogatories are established methods of discovery that are permissible under civil practice rules. Depositions involve taking sworn testimony from a witness, which can be critical for gathering facts and clarifying uncertainties about the case. Interrogatories, on the other hand, are written questions that one party sends to another requiring written responses under oath. Both methods are formalized, allowing for structured disclosure processes and providing legal weight to the information obtained.

The other options do not conform to the structured methods of obtaining disclosure recognized by the rules of civil procedure. Verbal agreements, for instance, lack the formal mechanisms of documentation and accountability that are important in legal processes. Informal requests without notice do not provide the necessary formality and can lead to misunderstandings, while exclusively using written motions limits the scope of discovery to what can be presented in motion practice rather than allowing for the broader range of evidence gathering through the methods sanctioned by the civil procedures. Thus, option A is significant as it upholds the integrity and thoroughness of the discovery process.